Perceptual processing techniques for video transcoding

Abstract

Systems and methods of video transcoding that employ perceptual processing techniques for enhancing the perceptual quality of transcoded video information, communications, entertainment, and other video content. Such systems and methods of video transcoding are operative to perform perceptual processing of an input video bitstream using predetermined information carried by the input bitstream. Having performed such perceptual processing of the input bitstream, the perceptual quality of transcoded video delivered to an end user is significantly improved.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]Not applicableSTATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT[0002]Not applicableFIELD OF THE INVENTION[0003]The present application relates generally to systems and methods of video transcoding, and more specifically to systems and methods of video transcoding that employ perceptual processing techniques for enhancing the perceptual quality of transcoded video information, communications, entertainment, and other video content.BACKGROUND OF THE INVENTION[0004]Systems and methods of video encoding are known that employ quantization techniques for reducing the bits from video encoders. Such video encoders frequently employ quantization with varying step-sizes that can have substantial effects on the output bit rates of the video encoders, and on the perceptual quality (also referred to herein as a / the “quality of experience” or “QoE”) of encoded video information, communications, entertainment, and other video content (also...

AI Technical Summary

Benefits of technology

[0010]In accordance with the present application, systems and methods of video transcoding are disclosed that employ perceptual processing techniques for enhancing the perceptual quality (also referred to herein as a / the “quality of experience” or “QoE”) of transcoded video information, communications, entertainment, and other video content (also referred to herein as a / the “transcoded video”). Such systems and methods of video transcoding are operative to perform perceptual processing of an input video bitstream (also referred to herein as an / the “input bitstream”) using predetermined information carried by the input bitstream. Having performed such perceptual processing of the input bitstream, the QoE for transcoded video delivered to an end user is significantly improved.

[0016]By employing predetermined information carried by an input bitstream to classify each MB in each video frame in the input bitstream, creating distortion imperceptibility maps for the respective video frames using the classifications for the respective MBs, and performing perceptual processing of the respective video frames using the information contained in the distortion imperceptibility maps, enhanced perceptual quality of transcoded video information, communications, entertainment, and other video content delivered to an end user can be achieved.

Problems solved by technology

For example, such video encoders can employ larger quantization step-sizes to perform coarser quantization, which can decrease the output bit rates of the video encoders and diminish the QoE for the encoded video.

However, perceptual quantization approaches typically employed by video encoders for maintaining a consistent QoE in video sequences have drawbacks when employed in conjunction with video transcoders.

Because the video input of a video transcoder has typically already been encoded by an external video encoder with possibly unknown characteristics, the video transcoder employing a conventional perceptual quantization approach may classify the MBs of video frames from the video input based on inaccurate spatial variation, temporal variation, and / or brightness information for the respective MBs, resulting in the use of QPs that may not provide the best possible QoE for the transcoded video delivered to the end user.

For example, such problems with the classification of MBs of video frames within the video transcoder may be more likely to occur if the external video encoder has employed higher QPs for MBs that have higher spatial variation, higher temporal variation, and / or higher brightness.

Such use of higher QPs can significantly reduce the spatial variation, and can cause a video transcoder employing a conventional perceptual quantization approach to use a smaller QP when encoding such MBs, resulting in a waste of bits where the HVS is less likely to perceive such distortion.

However, a video transcoder employing a conventional perceptual quantization approach may not take into account such information when classifying the MBs.

However, video frames compressed according to the H.264 coding format do not generally carry such QP information for the MBs of video frames.

Further, a video transcoder employing a conventional perceptual quantization approach may not have the capability of estimating the QPs for such MBs of video frames compressed according to the H.264 coding format when the skip coding mode is employed.

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